KINETIC-STUDY OF THE CARBON-FILAMENT FORMATION BY METHANE CRACKING ONA NICKEL-CATALYST

A rigorous kinetic model for the formation of filamentous carbon on a nickel catalyst by methane cracking is derived. The experimental study was performed in an electrobalance unit. The temperature ranged from 773 to 823 K and the partial pressure of methane ranged from 1.5 to 10 bar. The mode of experimentation ensured that the rate of growth of t he carbon filaments was always based upon the same number of filaments . A kinetic model is selected in which the abstraction of the first hy drogen atom from molecularly adsorbed methane is the rate-determining step. Based on the results of the parameter estimation, an energy diag ram for the methane cracking is constructed. (C) 1997 Academic Press.